Two articles, mainly about dreary routine supporting order, are honest (4,3,5)
I believe the answer is:
tell the truth
'two articles mainly about dreary' is the definition.
I know nothing about this answer so I cannot tell whether this works.
'routine supporting order are honest' is the wordplay.
I cannot really see how this works, but
'routine' could be 'rut' (rut is a kind of routine) and 'rut' is found within the answer.
'order' could be 'tell' (synonyms) and 'tell' is located in the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for tell the truth that I've seen before include "Speak honestly" , "Don't lie" , "Be honest" .)